Estratégias para conservação de germoplasma de abacaxizeiros

Abstract

The pineapple plant is a tropical fruiting species of great economic importance, so it is crucial to maintain its genetic variability through conservation programs. Therefore, the general objective of this work was to develop and validate conservation strategies to protect this germplasm. For that purpose, three experiments were conducted. The characterization work was carried out in field conditions with 46 accessions of different botanical varieties, obtained from the Germplasm Bank of the Embrapa Cassava and Fruits research unit, based on 21 morphological descriptors. The accessions were recovered from in vitro conservation after culture for 10 years, to evaluate the effect of long culture periods on the morphological traits and production cycle of the conserved varieties. An experiment was also carried out with pineapple pollen grains, aiming to develop a cryopreservation protocol for these structures. This experiment was conducted with 13 accessions of four botanical varieties, where the seed formation was also assessed. Finally, conservation in urban gardens was analyzed, involving selection of 30 yards for planting pineapple seedlings, according to previously defined criteria of the homeowners. The experimental design was completely randomized with a total of nine seedlings per yard with different potential uses (ornamentation and/or food). With respect to the accessions kept under in vitro conservation for 10 years, only accessions BGA-003 and BGA-020, both belonging to the variety Ananas comosus var. bracteatus, demonstrated genetic instability based on the morphological characterization. The cryopreservation of the pollen grains was possible after dehydration treatment for 6 hours on silica gel, with good in vitro germination rates and production of viable seeds. Finally, the model of conservation in urban gardens was viable, although requiring careful planning for efficiency. The results obtained support improved preservation of pineapple germplasm